Question

Is the following definition of perpendicular reversible? If yes, write it as a true biconditional.
Two lines that intersect at right angles are perpendicular.
The statement is not reversible.
Yes; if two lines intersect at right angles, then they are perpendicular.
Yes; if two lines are perpendicular, then they intersect at right angles.
Yes; two lines intersect at right angles if (and only if) they are perpendicular.

Answer 1

A biconditional statement is a statement in which it is inherently true but when the clauses are exchanged, the statement would still be regarded as true. In this case, the statement is biconditional. The answer that would make sense here would be C. Yes; if two lines are perpendicular, then they intersect at right angles.

Answer 2

The correct answer is:

Yes; two lines intersect at right angles if (and only if) they are perpendicular.

Explanation:

If two lines intersect at right angles, they are by definition perpendicular.

If two lines are perpendicular, they, by definition intersect at right angles.

This means that two lines are perpendicular if and only if they intersect at right angles.